Indicating fuse holder



Feb. 26, 1957 E. v. SUNDT INDICATING FUSE HOLDER Filed Dec. 25, 1953 IN VEN TOR.

United States Patent INDICATING FUSE HOLDER Edward V. Sundt, Wilmette, Ill., assignor to Sundt Engineering Company, Des Plaines, Ill., a corporation of Illinois Application December 23, 1953, Serial No. 399,977

15 Claims. (Cl. 200-121) This invention relates to an indicating fuse holder.

The principal object of this invention is to provide an improved indicating fuse holder, which occupies a minimum of both panel space and cubical content, which is simple and rugged in construction, which carries within its enclosure the cartridge fuse and an indicating lamp for indicating when the fuse has operated or blown, which includes a cover containing the indicating lamp and spring clips for releasably carrying the cartridge fuse, which includes a base having spring clip members connected into the electrical circuit and which receive the fuse receiving spring clips for fusing the electric circuit and for detachably securing the cover to the base, which includes telescoping parts on the cover and base for guiding the cover onto the base, which includes a contoured surface on the cover for readily manually manipulating the cover with respect to the base, which has tongues integrally formed on the spring clips and the spring clip members for making and breaking the circuit as the cover is applied to and removed from the base, which has studs acting to secure the spring clip members to the base, to mount the fuse holder on a panel and the like and to electrically connect the fuse into the electric circuit to be protected, which has the indicating lamp and the cartridge fuse arranged in parallel to provide minimum cubical content and use of minimum panel space, which has a light transmitting cover for passing light from the indicating lamp when the fuse is blown, which has the fuse receiving spring clips simply secured in the cover, which is fool-proof in operation, and which is simple and inexpensive to manufacture and install.

Further objects of this invention reside in the details of construction of the indicating fuse holder and in the cooperative relationships between the component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing, in which:

Fig. 1 is a perspective view of the indicating fuse holder of this invention;

Fig. 2 is a vertical sectional view through the indicating fuse holder taken substantially along the line 2-2 of Figs. 1 and 4;

Fig. 3 is a vertical sectional view taken substantially along the line 3-3 of Fig. 2 but showi g the cover separated from the base;

Fig. 4 is a vertical sectional view taken substantially along the line 4-4 of Fig. 2 and showing the cover applied to the base;

Fig. 5 is vertical sectional view through the cover;

Fig. 6 is a perspective view of one of the fuse receiving spring clips carried by the cover;

Fig. 7 is a perspective view of one of the spring clip members carried by the base. 7

The indicating fuse holder of this invention is generally designated at 10. It includes an elongated base 11 made of electrical insulating material, preferably a thermosetting plastic such as Bakelite or the like. The indicating fuse holder also includes an elongated cover 12 made of light transmitting electrical insulating material, preferably a thermoplastic material such as nylon or the like.

The elongated electrical insulating base 11 has a bottom wall 14 and side walls 15 which provide an elongated cavity 16 in the base. The center of the bottom wall 14 is provided with an upwardly extending boss 17 and the bottom wall 14 is provided with a pair of downwardly extending circular bosses 18.

Carried at each end of the cavity 16 in the base 11, is a spring clip member 20. These spring clip members 20 are substantially U shaped and are provided with a pair of spaced apart spring arms 21 and a spring tongue 22. The bottoms of these spring clip members are each provided with a hole for the reception of a screw threaded stud 23. The spring clip members 22 are arranged in the bottom of the cavity 16 of the base 11 against the central boss 17 with their tongues 22 outwardly disposed. The studs 23 extend through the holes in the spring clip members 20 and through holes in the circular bosses 18, the studs 23 having square heads 24 which also engage the central boss 17 to prevent turning of the studs. The studs 23 operate to secure the spring clip members 20 in the base 11, to provide electrical connections to the spring clip members 20 for including the same in an electric circuit to be protected, and mount the base on a panel 27 or the like. In this latter respect, the circular bosses 18 extend into suitable holes in the panel member 27 and electrical insulating washers 25 and nuts 26 secure the base 11 to the panel 27. The circular bosses 18 and the electrical insulating washers 25 electrically insulate the studs 23 from the panel 27.

The elongated electrical insulating cover 12 has a top wall 28 and side walls 29 defining an elongated cavity 32 therein. The side walls 29 are provided with an external shoulder 30 and a depending skirt 31 to be telescopically received in the base 11. The skirt 31 and the shoulder 30 therefore operate to guide the cover with respect to the base. The cavity 32 inside of the cover 12 is provided with an internal shoulder 33 having spaced projections 34. The sides of the skirt 31 have openings 35 which facilitate the insertion and removal of a cartridge fuse in the cover.

Carried in each end of the cavity 32 of the cover 12 is a fuse receiving spring clip 37. The spring clips 37 are substantially U shaped, each having a pair of spring arms 38. The spring clips 37 are each provided with four (4) cars 39 which are adapted to seat against the internal shoulder 33 of the cover 12. Each spring clip 37 is also provided with a spring tongue 40.

The internal shoulder 33 in the cavity 32 of the cover divides the cavity into an indicating lamp compartment adjacent the top wall 28 and a fuse compartment adjacent the skirt 31. Located in the indicating lamp c0m partment of the cavity 32 is an indicating lamp 42 which may be a conventional neon lamp. The lamp 42 is connected to one spring clip 37 by a wire 43 and to the other spring clip 37 by a wire 44, a resistance 45 and a wire 46. In this way, the indicating lamp 42 is connected in series with the resistance 45 and is connected across the spring clips 37.

After the indicating lamp 42 is so electrically connected to the spring clips 37, the spring clips are forced into the cover 12 until their ears 39 engage the internal shoulder 33 in the cavity. In so doing, the side walls of the cover are distended outwardly. The spring .clips 37 are then heated, preferably by induction heating, to cause the thermoplastic material of the cover, where it is engaged by the cars 39, to melt. As a result, the side walls of the cover resume their original shape and the ears 39 become embedded in the side walls of the cover, permanently to secure the spring clips 37 in the cover. The proper spacing of the spring clips 37 is assured by the spacing lugs 34 in the cover.

The spring clips 37 releasably receive the end caps 49 of a conventional cartridge fuse 48. In this way, the cover 12. carries the indicating lamp 42 and the cartridge fuse 48 in parallel relation so that the fuse holder will occupy a minimum of both panel space and cubical content. The openings 35 in the skirt 31 permit ready manipulation of the cartridge fuse 48 with respect to the spring clips 37.

When the cover 12, carrying the cartridge fuse 43, is applied to the base 11 it is guided by the telescoping skirt 31. The fuse receiving spring clips 37 are received in the spring clip members 20 carried by the base and this action performs two functions, to secure the cover to the base and to connect electrically the caps of the fuse 48 to the studs 23 for fusing the electric circuit to be protected. As the cover is being applied to and removed from the base, the spring tongues 22 and 40 of the spring clip members and the spring clips resiliently contact each other for making and breaking the electric circuit. In other words, these spring tongues 22 and 40 operate to make and break the electric circuit independently from the spring arm portions 21 and 38 of the spring clips and spring clip members. To facilitate manual manipulation of the cover 12 with respect to the base 11 the side walls of the cover are contoured. For this purpose, as illustrated in the drawing, the side walls are made concave to provide a suitable gripping surface.

After the cover with its cartridge fuse has been applied to the base, and an overload occurs in the electric circuit, the cartridge fuse operates or blows, and as a result, the indicating lamp is connected into the circuit and is illuminated upon the blowing of the fuse. The light generated by the indicating lamp is transmitted through the cover 12 to indicate that the fuse has operated or blown. When this condition occurs, the cover may be readily removed and the cartridge fuse replaced.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and therefore this invention is to be limited to the appended claims.

' I claim as my invention;

1. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for the base and having an elongated cavity therein, telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities, an indicating lamp carried lengthwise in the elongated cavity of the cover, a

substantially U-shaped outwardly facing fuse receiving spring clip carried by the cover in the cavity adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown.

2. In an indicating fuse holder for a cartridge fuse, an

elongated electrical insulating base, a substantially U- shaped spring clip member carried by the base adjacent each end thereof means for electrically connecting the spring clip members into an electric circuit, an elongated electrical insulating and light transmitting cover for the base, an indicating lamp carried in the cover lengthwise thereof, a substantially U-shaped fuse receiving spring clip carried by the cover adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, mean-s electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, and the sides of said elongated cover being contoured to facilitate manual manipulation of the cover with respect to the base.

3. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for/the base and having an elongated cavity therein, telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities, an indicating lamp carried lengthwise in the elongated cavity of the cover, a substantially U-shaped outwardly facing fuse receiving spring clip carried by the cover in the cavity adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, and the sides of said cover being contoured to facilitate manual manipulation of the cover with respect to the base.

4. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, studs extending through the spring clip members and the base for securing the spring clip members to the base, for mounting the fuse holder and for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for the base and having an elongated cavity therein, telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities, an indicating lamp carried lengthwise in the elongated cavity of the cover, a substantially U-shaped outwardly facing fuse receiving spring clip carried by the cover in the cavity adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown.

5. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover forthe base and having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment in the cover cavity, a substantially U-shaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cover cavity adjacent each end thereof and having ears engaging the shoulder and the sides of the cavity for securing the same in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, and telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities.

6. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, studs extending through the spring clip members and the base for securing the spring clip members to the base, for mounting the fuse holder and for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for the base and having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment in the cover cavity, a substantially U-shaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cover cavity adjacent each end thereof and having ears engaging the shoulder and the sides of the cavity for securing the same in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, and telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities.

7. In an indicating fuse holder for a cartridge fuse, an electrical insulating and light transmitting thermoplastic cover having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment of the cavity, a substantially Ushaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cavity and having ears engaging the shoulder and the sides of the cavity and heat sealed into the sides of the cavity for securing the spring clips in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, and means for electrically connecting the lamp across the spring clips.

8. in an indicating fuse holder for a cartridge fuse, an electrical insulating and light transmitting thermoplastic cover having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment of the cavity, a substantially U-shaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cavity and having ears engaging the shoulder and the 6 sides of the cavity and heat sealed into the sides of the cavity for securing the spring clips in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, and means for electrically connecting the lamp across the spring clips, the sides of said cover adjacent the fuse compartment having openings to facilitate insertion and removal of the cartridge fuse.

9. In an indicating fuse holder for a cartridge fuse, an electrical insulating and light transmitting thermoplastic cover having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment of the cavity, a substantially U-shaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cavity and having ears engaging the shoulder and the sides of the cavity and heat sealed into the sides of the cavity for securing the spring clips in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, and means for electrically connecting the lamp across the spring clips, the sides of the cover adjacent the lamp compartment being contoured to facilitate manual manipulation of the cover.

10. In an indicating fuse holder for a cartridge fuse having a thermoplastic cover provided with a cavity having an internal shoulder and a pair of substantially U- shaped fuse receiving spring clips provided with ears, the method of securing said spring clips in the cavity against the shoulder comprising the steps of forcing said spring clips into the cavity with the ears thereof engaging the shoulder and engaging and distending the side walls of the cavity, and induction heating the spring clips to cause their ears to melt the side walls of the cavity where they are engaged by the ears to allow the side walls to resume their normal position and thereby imbed the ears in the side walls.

11. In a fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein having a central boss, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof and the central boss, studs extending through the spring clip members and the base and having square heads engaging the boss for securing the spring clip members to the base, for mounting the fuse holder and for electrically connecting the spring clip members into an electric circuit.

12. In a fuse holder for a cartridge fuse, an electrical insulating base, a pair of substantially U-shaped spring clip members carried by the base in spaced apart relation, means for electrically connecting the spring clip members into an electric circuit, an electricalinsulating cover for the base, a pair of substantially U-shaped fuse receiving spring clips carried by the cover in spaced apart relation for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse on said cover, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electrical circuit and for releasably securing the cover to the base, each of said spring clip members and spring clips being integrally provided with tongues which engage each other as the cover is being applied to and removed from the base for making and breaking the circuit.

13. In an indicating fuse holder for a cartridge fuse, an elongated electrical insulating base, a substantially U- shaped spring clip member carried by the base adjacent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an elongated electrical insulating and light transmitting cover for the base, an indicating lamp carried in the cover lengthwise thereof, a substantially U-shaped fuse receiving spring clip carried by the cover adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, means electrically connecting the lamp across the fuse receiving spring clips, said "fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, each of said spring clip members and spring ciips being integrally provided with tongues which engage each other as the cover is being applied to and removed from the base for making and breaking the circuit.

14. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially U-shaped and outwardly facing spring clip member carried by the base in the cavity adja cent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for the base and having an elongated cavity therein, telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities, an indicating lamp carried lengthwise in the elongated cavity of the cover, a substantially U-shaped outwardly facing fuse receiving spring clip carried by the cover in the cavity adjacent each end thereof for receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of said cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, each of said spring clip members and spring clips being integrally provided with tongues which engage each other as the cover is being applied to and removed from the base for making and I breaking the circuit.

15. In an indicating fuse holder for a cartridge fuse, an electrical insulating base having an elongated cavity therein, a substantially Ll-shaped and outwardly facing spring clip member carried by the base in the cavity adjacent each end thereof, means for electrically connecting the spring clip members into an electric circuit, an electrical insulating and light transmitting cover for the base and having an elongated cavity therein, said cavity having an internal shoulder dividing the cavity into a lamp compartment and a fuse compartment, an indicating lamp located lengthwise in the lamp compartment in the cavity, a substantially U-shaped outwardly facing fuse receiving spring clip located in the fuse compartment of the cover cavity adjacent each end thereof and having ears engaging the shoulder and the sides of the cavity for securing the same in place, said spring clips holding the lamp in place in the cover and receiving the ends of a cartridge fuse to releasably mount the cartridge fuse lengthwise of the cover parallel to the lamp, means for electrically connecting the lamp across the fuse receiving spring clips, said fuse receiving spring clips being received in the spring clip members of the base when the cover is applied to the base for fusing the electric circuit and for releasably securing the cover to the base, and said lamp being illuminated for transmitting light through the cover when the cartridge fuse is blown, and telescoping means on the base and cover for guiding the cover on the base and for enclosing the elongated cavities, each of said spring clip members and spring clips being integrally provided with tongues which engage each other as the cover is being applied to and removed from the base for making and breaking the circuit.

References Cited in the file of this patent UNITED STATES PATENTS 894,704 Sargent July 28, 1908 1,106,974 Rush 1 Aug. 11, 1914 1,641,203 Scordamaglia Sept. 6, 1927 1,760,002 Romrner May 27, 1930 2,091,204 Horn Aug. 24, 1937 2,177,989 Kitto Oct, 31, 1939 2,333,942 La Mar Nov. 9, 1943 2,343,676 La Mar Mar. 7, 1944 

